双馈风力发电机的小信号稳定分析及其控制研究

Analysis of small-signal stability and control strategy of the grid integrated wind plant based on DFIG

电网对直接并网的兆瓦级风电场的要求已经从电能质量进一步发展到暂态稳定、事故后自动恢复、调频调压、直接调度等,因而功率输出平稳,可调性强的双馈入异步风力发电机逐渐成为主流风机。双馈入异步发电机由于采用磁场定向的矢量变换控制技术,通过对用于励磁的PWM变频器各分量电压、电流的调节,从而实现发电机有功和无功的解耦控制。因此建立了双馈入风力发电机的详细模型,制定相应的控制策略,并通过小信号法和动态仿真对双馈入风力发电机的小扰动稳定进行分析和评估。

The prompt development of wind power is put forward even more requirement for the direct grid integration of MW wind generation plant such as transient stability, automacic recovery after faults, modulation of frequency and voltage, direct dispatch,etc.Hence the DFIG with smooth output and good controllability is the dominating wind turbine. The decoupled P-Q control is well implemented by DFIG based on PWM vector via the modulation of rotor d-q current. Therefore, the detailed model of the power plant based on DFIG and corresponding control strategy is established. The small-signal stability is studied and assessed via a small-signal analysis, which is further verified by dynamic simulation.